Wood-boring beetles are among the most significant insect pests affecting trees in our area. Although these beetles are seldom the primary cause of a tree’s stress, their presence is a clear indicator of rapidly declining tree health. An infestation by these beetles serves as a critical alert: without prompt intervention, the tree is likely to die. Unfortunately, by the time these beetles are detected, it is often already too late to save the affected tree.
When trees become stressed and their natural defenses are compromised, wood-boring beetles will exploit the tree’s vulnerability and lay their eggs in the tree’s bark crevices. Depending on the species, a single beetle can deposit more than 100 eggs. These eggs hatch into larvae, which is the most devastating life phase. The larvae burrow radially through the tree’s living tissues, disrupting the essential transfer of nutrients and water from the roots to the canopy. Eventually, the larvae form pupal chambers where they mature into adults. Upon emerging, these adults leave behind distinctive “Borer Exit holes.” The combined effect of this damage and other environmental stresses can ultimately lead to the tree’s demise and even compromise the structural integrity of the tree.
Numerous species of wood-boring beetles exist in our area, yet the damage they inflict, their life cycles, and the methods for their management share striking similarities across species. This article aims to provide a foundational understanding of wood-boring beetles, outlining effective prevention strategies and treatment options for those encountering an infestation.
Prevention of Wood-Boring Beetles
Effective prevention of wood-boring beetle infestations is straightforward and centers on maintaining robust tree health. By ensuring your tree’s basic needs are met, it can leverage its natural defenses to ward off these pests. Beetles can also detect stressed trees, so healthy trees often do not even get targeted. Here are essential steps to keep your trees healthy in Central Texas:
- 1. Excavate the Root Collar: Clear debris and soil away from the base of the tree to prevent rot and other diseases.
- 2. Mulch the Root Zone: Clear debris and soil away from the base of the tree to prevent rot and other diseases.
- 3. Consistent Watering: Water your trees regularly and deeply to promote strong and deep root growth.
- Call your favorite arborists if you need help keeping your trees healthy! 512-585-1762
Treatment
Effectively managing wood-boring beetles in trees typically requires chemical interventions due to the pests’ hidden nature beneath the bark, making them challenging to isolate and detect.
Recommended Treatments:
- 1. Soil Drench with Imidacloprid: This is our preferred initial treatment upon detecting wood-boring beetles. Imidacloprid is a systemic insecticide that penetrates the tree’s living tissues, poisoning the beetles as they feed on the phloem. This treatment has the added benefit of providing protection for up to a year, which gives you the time to alleviate other stress factors affecting the tree.
- 2. Bark Spray with Bifenthrin and Pentrabark: For a more direct approach on severe infestations, I recommend applying a bark spray that combines bifenthrin with Pentrabark. This should be done 2-3 times at two-week intervals. Bifenthrin effectively kills beetle larvae upon contact, while Pentrabark aids in penetrating the bark to reach the hidden larvae. Timing these treatments in late spring or during active infestations can yield the best results.
These methods are generally effective against various species of wood-boring beetles in Central Texas. I will generally recommend and perform both upon first detecting the beetles to give the tree the best chance to recover. As a future precaution, when the Emerald Ash Borer becomes prevalent in our region, trunk injections of Emamectin Benzoate will become a critical defense strategy. However, these injections are not commonly necessary for other beetle infestations at this time.
Integrating Pest Management with Tree Health:
It’s crucial to understand that merely treating the beetles is not enough. Addressing the underlying health issues that made the tree vulnerable to infestation is essential. I strongly recommend working with a professional arborist to tackle all stress factors impacting your trees. This holistic approach ensures the long-term health and protection of your trees against future infestations.
Contact a Tree Amigos arborist today to get expert help in protecting your trees from wood-boring beetles and enhancing their overall resilience.
DIY Treatments for Wood-Boring Beetles
Embrace the Do-It-Yourself spirit and take control of wood-boring beetle infestations in your trees with our recommended treatments. Please ensure you read all pesticide labels thoroughly and wear the appropriate personal protective equipment during application.
Face shield for spraying Pesticides: https://amzn.to/3UgHxAB
Long gloves for handling Pesticides: https://amzn.to/4aVqF9G
- DIY Soil Drench
- Materials Needed:
- 1. Imidacloprid Tree & Shrub Drench: Purchase here
- 2. 5-gallon bucket: Purchase here
- Instructions:
- 1. Follow the instructions on the Imidacloprid bottle to mix the solution with water in the 5-gallon bucket.
- 2. Gradually pour the mixture around the base of the tree, ensuring even distribution.
- 3. Wear long rubber gloves and a face shield during application for your safety.
Instructions:
1. Carefully read and follow the instructions on both the Pentrabark and Baseline labels.
2. Mix the Pentrabark and Baseline in the pesticide sprayer as directed.
3. Apply the mixture liberally to the stem and scaffolding branches of the tree using the sprayer.
4. Ensure you are wearing long rubber gloves, long pants, and a face shield for protection.
By following these guidelines, you can effectively treat wood-boring beetle infestations and protect your trees from further damage. Remember, safety is paramount, so always adhere to the recommended precautions.
Author: Andrew Anstrom
Board Certified Master Arborist
